Lions receiver Kris Durham hauls in a tough 4-yard catch last week in a preseason game against Oakland. AP File Photo

ALLEN PARK -- Ryan Broyles spent the first couple weeks of training camp on the roster bubble, but has played well enough that his job should be safe.

That doesn't mean the Detroit Lions are any closer to figuring out what to do at the position.

The rest of the receivers continue to play well enough that Broyles' emergence hasn't really solved anything. It's just bumped someone else onto the bubble.

That someone appears to be Kris Durham.

He spent most of last season as the Lions' No. 2 receiver and finished with 490 yards, trailing only Calvin Johnson. But he also struggled with drops and gaining separation.

ProFootballFocus rated Durham No. 110 among receivers who played at least 25 percent of their team's offensive snaps. That's out of 111.

Durham, according to PFF, was the second-worst wideout in the NFL.

"There were a lot of things I needed to get better on," Durham said. "I did what I was asked to do, but I definitely left a lot of plays out there on the field that I need to work on."

Durham, to his credit, appears to have done that.

He's played well in training camp -- well enough, he started each of Detroit's first two preseason games with Johnson out.

He hauled in an acrobatic 4-yard touchdown catch against the Raiders, one of the best plays of camp.

"Kris is smart," coach Jim Caldwell said. "He does a good job just in terms of understanding the offense. He caught the ball well last week. He blocks for us well."

Durham is on the bubble, but not because he's had a bad camp. It's just that Detroit also has Johnson and Golden Tate, plus Jeremy Ross because of what he offers in the return game.

Throw in Kevin Ogletree and Broyles, who both appear safe, and the Lions' top five receivers appear set heading into Friday night's exhibition against the Jacksonville Jaguars.

Durham suddenly finds himself in a battle with fast-rising Corey Fuller for the sixth receiver spot, assuming the Lions keep that many.

"We try not to focus on that because those decisions aren't up to me," Durham said.

Fuller is more of an unknown commodity than Durham, but has made huge leaps since Detroit took him in the sixth round of last year's draft.

He doesn't have Durham's experience, but might have a higher ceiling.

"My potential," he said, when asked why he should stick on the 53-man roster. "I've improved so much from last year to this year, and I just can't wait to see what happens further down the line. I really don't know how good I could be.

"I was very raw last year. I still think I'm a little raw now, and still got a whole lot to learn."

Fuller played quarterback in high school, didn't play at all at Kansas and was a full-time receiver just one season after transferring to Virginia Tech.

Now he might be the Lions' most improved player from 2013 to 2014, highlighted by hauling in a 21-yard game-winning touchdown pass in the final minutes of the exhibition opener against Cleveland.

Fuller is eligible to return to the practice squad, though he's played well enough that Detroit could lose him to another team if he's not included on the 53-man roster.

For the Lions, the situation might come down to this: Going with the guy who offers more right now (Durham), or gambling on the guy who could offer more in future seasons (Fuller).

"I have no idea what I'd do," Tate said. "And that's a good problem to have."